Thread coating device



1956 J. H.ATKINS ET AL THREAD COATING DEVICE Filed April 2, 1963 fllllllllllll INVENTORS JOHN H. ATKINS MCGOWAN, JR.

JOHN

Ill

IIIIIIIII FIGI FIG.3

FIGZ

ATTORNEYS United States Patent 3,291,097 THREAD CGATING DEVICE John Howard Atkins, Lexington, and John McGowan,

in, West Roxbury, Boston, Mass., assignors to Oversewing Machine Company of America, Medford, Mass.,

a corporation of Massachusetts Filed Apr. 2, 1963, Ser. No. 270,081 3 Claims. (Cl. 118109) This invention relates generally to thread coating devices and more particularly comprises a new and improved unit for applying a consistently even coating of liquid adhesive or the like to a traveling length of thread.

In the manufacture of various types of products that are assembled, either in whole or in part, by a sewing operation, it is sometimes advantageous that all or a portion of the thread employed in the sewing process be coated with an adhesive. For example, in bookbinding and in particular in the manufacture of oversewn books, it is desirable that the shuttle thread be coated or saturated with a liquid adhesive before being fed by the shuttle through the registering needle thread loops. A book which is sewn with an adhesive covered shuttle thread may be produced quicker and at a lower cost than by other methods. Previously the practice had been to coat the inner marginal edges of each section before sewing it in place. The purpose of the adhesive coating is to insure a firm bond between adjoining sections and to prevent the needle threads from being exposed when the book is opened.

By applying a liquid adhesive to the shuttle thread prior to its being engaged with the needle threads, the requirement of applying adhesive to the marginal edges of each section is eliminated. It will be appreciated that the adhesive covered shuttle thread furnishes the necessary bonding between adjoining sections of the book.

Heretofore, the devices employed for applying the liquid adhesive coating to the shuttle threads have not been particularly satisfactory since threading of the devices has been somewhat difficult and messy and normally involves looping the thread under a hook located below the surface level of the liquid adhesive. In addition, the thread must then be passed out through a restricted opening normally surrounded by a wiping element which further restricts the opening. Furthermore, the thread pasting devices currently available are subject to relatively rapid wear caused by the abrasive characteristics of the traveling thread.

In any event devices of this sort have not proven to be entirely satisfactory and it is an object of the present invention to provide improvements in devices for applying a coating of liquid or semi-liquid material to lengths of traveling threads.

Another object of this invention is to provide improvements in thread-pasting devices.

Still another object of this invention is to provide an efficient, readily threadable device for coating and/or saturating lengths of traveling threads.

Yet another object of this invention is to provide a thread-coating unit of durable and rugged construction which is adapted to apply a consistently even coating to lengths of thread passed therethrough.

More particularly, this invention features a device for coating a traveling thread comprising a container adapted to receive a quantity of material such as a liquid adhesive or the like and having a tubular member with one end passing out through a wall of the container below the surface level of the liquid material and the opposite end thereof extending above the surface level. A cover member is provided and carries a second tubular member somewhat larger than the first tubular member and "Ice adapted to be telescoped over the first tubular member. In practice, the thread which is to be coated is fed from the outside of the container and inserted down through the first tubular member. Thereupon the cover is applied with the result that, as the second tubular member telescopes over the first member its lower edge engages a section of the thread to force it below the surface level of the liquid. As the thread is drawn through the device, is it passed first down into the liquid and then upwardly between the walls of the two tubular members and then down through the first tubular member from whence it passes out of the container for subsequent use.

As an added feature of this invention, a wiping element is furnished for applying a continuously even pressure against the thread so as to wipe away excess liquid and thereby provide a uniform coating on the thread. As still another feature of this invention the first tubular member is provided with a rotatable wearing collar whereby as the collar becomes gradually worn under the action of the thread it may be rotated to a new position to provide a fresh wearing surface.

But these and other features of the invention, along with further objects and advantages thereof, will become more readily apparent from the following detailed description of a preferred embodiment of the invention with reference being made to the accompanying drawings, in which;

FIGURE 1 is a view in side elevation of a threadcoating device made according to the invention;

FIGURE 2 is a cross-sectional view, somewhat enlarged, taken along the line 22 of FIGURE 1; and

FIGURE 3 is an exploded perspective view of the de vice.

Referring now to the drawings, the reference character 10 generally indicates an applicator for coating or saturating a length of traveling thread 12 with a material such as a liquid or semi-liquid adhesive 14 or the like. In the illustrated embodiment, the applicator comprises a cylindrical container 16 adapted to hold a quantity of the liquid substance 14 and is formed with a central opening 13 in a bottom wall Ztl thereof. A cylindrical tube 22 is fixed to the bottom wall 29 in register with the opening 18 and extends upwardly within the container 16 to a height substantially even with the upper edges of the container. It will be noted that the upper edges of the cylindrical container walls are recessed or notched at 24- and 26 for reasons that will presently appear.

Detachably and rotatably mounted to the upper end of the tube 22 is a bushing 28 which is formed with an inwardly turned upper edge which forms a shoulder 36 mating smoothly with the upper edge of the tube 22 as best shown in FIGURE 2. The upper turned edge of the bushing is smoothly rounded and provides an adjustable wearing surface for the traveling thread 12. Preferably, this bushing is fabricated from stainless steel or some other material characterized by a hard smooth wearing surface.

A cover 32 is provided for the container and is formed with a flanged portion 34 having a peripheral lip 36 dimensioned to fit snugly onto the top of the container 16. A recess 33 is formed in the outer edge of the flanged portion 34 and registers with the recess 26 formed in the container 16. On the opposite side of the flanged portion 34 there is mounted a radial stud 40' adapted to be received in the recess 24 when the cover is mounted in place. This will assure the cover recess 38 will be in precise registration with the container recess 26. It will also be understood that the cover may be rotated so as to locate the stud 4-0 in the recess 26 and register the recesses 24 and 38. As shown in FIGURES l and 2,

3 the recesses 26 and 38 define an opening through which the thread 12 enters the applicator.

Formed as an integral part of the cover 32 is a cylindrical tube 42 located centrally of the flanged portion 34. The tube has an inside diameter somewhat greater than the outside diameters of both the tube 22 and its bushing 28 so as to define an annular space 44 between the walls thereof when the cover 32 is in place. The length of the tube 42 is slightly less than the length of the tube 22 so as to provide clearance between the bottom wall 20 and the lower annular edge of the tube 42. It will be appreciated that, with this construction, the traveling thread 12 will pass into the applicator through the registered recesses 26 and 38 and thence will be drawn first downward-1y below the surface level of the liquid adhesive 14 and then upwardly through the annular space 44 and over the top of the bushing 28. From the bushing 28, the thread will be passed down through the tube 22 and out through the opening 18. With this arrangement, the thread is automatically carried into the liquid adhesive whenever the cover is placed on top of the container. It will be understood that feeding a fresh section of thread through the applicator is greatly facilitated since it may be done Without the need of passing the thread through the adhesive. It is necessary only to remove the cover 32 and insert the free end of the thread down through the tube 22 and out through the opening 18. The following portion of the thread is then placed in the notch 26 and the cover is replaced. As the cover is placed into position, the lower edge of the tube 42 will engage a section of the thread and carry it below the surface of the liquid adhesive 14.

The cover 32 will be seen to include an annular collar 46 located on the upper side of the flanged portion 34 and in alignment with the tube 42. The function of the collar 46 is to center a wiping device 48 which removes excess liquid from the thread. The wiping device includes a pointed cylindrical stem 50 preferably of stainless steel or the like, and having its rubber end embedded in a knob 52 formed of hardened rubber, plastic, or the like. A relatively thick annular felt pad 54 is slipped over the stem 50 and mounted butt against the knob 52. The stem 50, it will be noted, is dimensioned to pass freely down through the tube 22 and to leave sufficient clearance as to permit passage of the thread 12. With the wiping device placed in its normal position, as shown in FIGURE 2, the lower surface of the pad 54 will rest against the upper annular surface of the bushing 28 so that the thread 12, passing over the bushing, will be wiped by the pad. The weight of the wiping device will apply sufficient pressure to the thread to remove excess 'adhesive from the thread and insure that a consistently even coating is applied. The wiping device may be rotated from time to time to bring a fresh section of the pad to bear against the thread whenever necessary and the entire pad is readily replaceable should it become worn beyond use. Also, the wiping device may be readily removed periodically to check the level of the liquid adhesive 14.

Extending outwardly from the cylindrical wall of the container 16 is a post 56 which is adapted to be received in an opening 58 formed through a hub 60 of a support bracket having an integral depending arm. The hub is tapped at 64 to receive a set screw 66 for clamping the post 56 tightly to the hub and the arm is provided with a plurality of openings 68 to permit the bracket to be fastened to a suitable support. With this arrangement the applicator may be readily dismounted from its supporting bracket for periodic cleaning.

In practice, the container 16 and its cover 32 may be fabricated from a suitable material such as brass or the like and plated with chrome or nickel to provide a hard outer surface that is smooth, easily cleanable, and inert to any liquids which normally will be contained therein.

The device offers a number of advantages not previously available, and these include quick and easy threading of fresh lengths of thread, a consistently even coating applied to the thread, wearing parts that are movable to utilize unworn portions thereof, and a unit that is readily cleansable. In addition, the thread may be fed from either side of the applicator and may be delivered in any direction from the opening 18 at the base of the container. As an added advantage the frictional drag of the thread passing through the applicator is substantially less in the normal direction of travel than in a reverse direction. This is due to the geometry of the thread travel in cooperation with the felt wiper and this differential in frictional drag minimizes the possibility of an operator running the thread through the applicator in the wrong direction.

While the invention has been described with particular reference to the illustrated embodiment, it will be understood that numerous modifications thereto will appear to those skilled in the art. For example, instead of the single thread shown a number of threads might be fed simultaneously through the applicator by providing additional notches about the rim of the container and the edge of the cover. It will therefore be understood that the above description and accompanying drawings should be taken as illustrative of the invention and not in a limiting sense.

Having thus described the invention, what we claim and desire to obtain by Letters Patent of the United States is:

1. A device for applying a coating of liquid to a length of travelling thread, comprising a container for receiving a quantity of said liquid, a first tubular member mounted in fixed position to a bottom wall of said container, said bottom wall being formed with an opening in register with the lower end of said first tubular member, the opposite end of said first tubular member extending above the normal surface level of said liquid, a cover detachably mounted to said container, a second tubular member mounted to said cover member and telescoped over said first tubular member, said second tubular member having an inside diameter greater than the outside diameter of said first tubular member to define an annular passage between said tubular members, the lower end of said second tubular member defining a space between the lower end thereof and said bottom wall, said container being formed with an opening above said normal surface level whereby a length of thread fed into said container through said opening above the surface level and through said first tubular member will have a section thereof drawn below the surface of said liquid by the end of said second tubular member engaging said thread.

2. A device according to claim 1 including a bushing detachably and rotata'bly mounted at said opposite end of said first tubular member.

3. A device according to claim 1 including a detachably and rotatably mounted pad disposed at said opposite end of said first tubular member and bearing against said thread for removing excess liquid therefrom.

References Cited by the Examiner UNITED STATES PATENTS 512,146 l/1894 Avis 1l8420 X 3,170,968 2/1965 Mitsuru Rokunohe et al.

CHARLES A. WILLMUTH, Primary Examiner. I. P. MCINTOSH, Ass st nt Examiner. 

1. A DEVICE FOR APPLYING A COATING OF LIQUID TO A LENGTH OF TRAVELLING THREAD, COMPRISING A CONTAINER FOR RECEIVING A QUANTITY OF SAID LIQUID, A FIRST TUBULAR MEMBER MOUNTED IN FIXED POSITION TO A BOTTOM WALL OF SAID CONTAINER, SAID BOTTOM WALL BEING FORMED WITH AN OPENING IN REGISTER WITH THE LOWER END OF SAID FIRST TUBULAR MEMBER, THE OPPOSITE END OF SAID FIRST TUBULAR MEMBER EXTENDING ABOVE THE NORMAL SURFACE LEVEL OF SAID LIQUID, A COVER DETACHABLY MOUNTED TO SAID CONTAINER, A SECOND TUBULAR MEMBER MOUNTED TO SAID COVER MEMBER AND TELESCOPED OVER SAID FIRST TUBULAR MEMBER, SAID SECOND TUBULAR MEMBER HAVING AN INSIDE DIAMETER GREATER THAN THE OUTSIDE DIAMETER OF SAID FIRST TUBULAR MEMBER TO DEFINE AN ANNULAR PASSAGE BETWEEN SAID TUBULAR MEMBERS, THE LOWER END OF SAID SECOND TUBULAR MEMBER DEFINING A SPACE BETWEEN THE LOWER END THEREOF AND SAID BOTTOM WALL, SAID CONTAINER BEING FORMED WITH AN OPENING ABOVE SAID NORMAL SURFACE LEVEL WHEREBY A LENGTH OF THREAD FED INTO SAID CONTAINER THROUGH SAID OPENING ABOVE THE SURFACE LEVEL AND THROUGH SAID FIRST TUBULAR MEMBER WILL HAVE A SECTION THEREOF DRAWN BELOW THE SURFACE OF SAID LIQUID BY THE END OF SAID SECOND TUBULAR MEMBER ENGAGING SAID THREAD. 